Position detection based on tissue discrimination

Abstract

A system is suggested comprising an optical sensing means and a processing unit. The optical sensing means may include an optical guide with a distal end, wherein the optical guide may be configured to be arranged in a device to be inserted into tissue in a region of interest. The processing unit may be configured to receive information of a region of interest including different tissue types as well as of a path through the tissues, to determine a sequence of tissue types along the path, to determine a tissue type at the distal end of the optical guide based on information received from the optical sensing means, to compare the determined tissue type with the tissue types on the path, to determine possible positions of the distal end of the optical guide on the path based on the comparison of tissue types, and to generate a signal indicative for the possible positions.

The invention claimed is: 
     
       1. A system for determining a position of an insertable medical device that is configured to be inserted into tissue of a patient during a medical procedure, comprising:
 a positioning device configured to be inserted through a path of the region of interest of tissue of a patient to position the insertable medical device, the positioning device including:
 an optical guide with a distal end, the optical guide being configured within the positioning device to emit light to a tissue segment at the distal end of the optical guide; 
 a light detector configured to be coupled to the optical guide and to detect light reflected by the tissue segment at the distal end of the optical guide as the positioning device is inserted through the path; and 
 a processor operatively coupled to the positioning device and configured to:
 (i) receive tissue type information of the region of interest, including different tissue types of the region of interest, 
 (ii) receive an input identifying the path to insert the positioning device through the region of interest, 
 (iii) determine a sequence of tissue types along the identified path based on the received tissue type information of the region of interest, 
 (iv) receive, from the light detector, the detected light of the tissue segment at the distal end of the optical guide as the positioning device is inserted into the region of interest, 
 (v) determine a tissue type of the tissue segment at the distal end of the optical guide based on the detected light, 
 (vi) determine possible positions of the positioning device along the path by comparing the determined tissue type of the tissue segment with the sequence of tissue types along the path, and generate a signal indicating the determined possible positions, and 
 (vii) detect a mismatch between the determined tissue type of the tissue segment and predicted tissue types for the determined possible positions, and generate a signal indicating the mismatch for prompting a user to adapt the placement of the insertable medical device. 
 
 
 
     
     
       2. The system of  claim 1 , further comprising a tracking device for tracking a position of the distal end of the optical guide relative to the region of interest, wherein determination of the possible positions is further based on the tracked position. 
     
     
       3. The system of  claim 2 , wherein the tracking device comprises elements for electromagnetic tracking, optical tracking and/or shape sensing. 
     
     
       4. The system of  claim 1 , wherein the processor is further configured to generate a visualization of the region of interest together with a virtual representation of the insertable medical device, in the region of interest, wherein a distal end of the virtual representation of the device is shown at a most probable position on the path. 
     
     
       5. The system of  claim 4 , further comprising an instrument for inserting the device into the tissue, wherein a position and orientation of the instrument is traceable by the tracking device, and wherein the generated visualization includes an indication of a relation of the instrument to the region of interest. 
     
     
       6. The system of  claim 1 , further comprising a video camera for imaging an operation field including the region of interest, wherein the processor is further configured to generate a combined visualization of the operation field and of inner structures of the region of interest. 
     
     
       7. The system of  claim 1 , further comprising an imaging system for generating information of a region of interest including different tissue types, wherein the imaging system is a medical imaging system out of the group consisting of an X-ray imaging system, a magnetic resonance imaging system, a computed tomography imaging system, and an ultrasound imaging system. 
     
     
       8. The system of  claim 1 , wherein the insertable medical device is a device out of the group consisting of a screw, a K-wire, an awl, and a tap. 
     
     
       9. A method of determining a position, utilizing a positioning device, of an insertable medical device insertable that is configured to be inserted into tissue of a patient during a medical procedure, the method comprising:
 receiving tissue type information of a region of interest of tissue of a patient, including different tissue types and an input identifying a path to insert the insertable medical device through the region of interest,
 determining a sequence of tissue types along the identified path based on the received tissue type information of the region of interest, 
 receiving, from a light detector coupled to the positioning device, detected light reflected from a tissue segment at a distal end of an optical guide of the positioning device, as the positioning device is inserted into the region of interest, 
 determining a tissue type of the tissue segment at the distal end of the optical guide based on the detected light, 
 determining possible positions of the positioning device along the path by comparing the determined tissue type of the tissue segment with the sequence of tissue types along the path, and generating a signal indicating the determined possible positions; 
 detecting a mismatch between the determined tissue type at the distal end and predicted tissue types for the determined possible positions; and 
 prompting a user to adapt the placement of the insertable medical device based on the detected mismatch. 
 
 
     
     
       10. The method of  claim 9 , further comprising the step of generating a visualization of the region of interest together with a virtual representation of the insertable medical device, in the region of interest, wherein a distal end of the virtual representation of the insertable medical device is shown at a most probable position on the path. 
     
     
       11. A computer program product comprising sets of instruction which, when executed on a processor of a system for determining a position of a device insertable into tissue according to  claim 1 , cause the processor to:
 (i) receive tissue type information of a region of interest of tissue of a patient, including different tissue types of the region of interest, 
 (ii) receive an input identifying a path to insert the device through the region of interest, 
 (iii) determine a sequence of tissue types along the identified path based on the received tissue type information of the region of interest, 
 (iv) receive, from a light detector coupled to the device, detected light reflected from a tissue segment at a distal end of an optical guide of the positioning device, as the positioning device is inserted into the region of interest, 
 (v) determine a tissue type of the tissue segment at the distal end of the optical guide based on the detected light, 
 (vi) determine possible positions of the positioning device along the path by comparing the determined tissue type of the tissue segment with the sequence of tissue types along the path, and generate a signal indicating the determined possible positions, and 
 (vii) detect a mismatch between the determined tissue type of the tissue segment and predicted tissue types for the determined possible positions, and generate a signal indicating the mismatch for prompting a user to adapt the placement of the insertable medical device.